Some of the presently known pivotal piston compressors are objectionable for various reasons. For example, one such pivotal piston compressor is characterized by a pivotal piston supported on a piston shaft and oscillating in a cylindrical housing. The housing is provided with at least one radially disposed partition to form a limit for the compression space. In this form, an effective sealing arrangement between the pivotal piston and the cylindrical housing walls is not possible, especially adjacent the end walls, so that compressed air can leak past the seals from the compresson chamber back into the intake chamber. Such leakage results in inefficiency and high or uncontrollable operating temperatures.
Another type of pivotal piston compressor is characterized by a spherical housing in which a circular or disc-type pivotal piston is employed. Since a continuous sealing element may be disposed on the circumference of the disc, leakage between the compression chamber and the intake chamber is thus reduced. The spherical housing, however, is divided at its greatest diameter into two sections thereby forming a juncture seam. This construction requires a more costly two-part piston to prevent passing over the seam, because a one-part piston would have to pass over the seam when oscillating, thereby causing rapid wear or destruction of the sealing element.
Moreover, in the above-described types of pivotal piston compressors, it is not feasible to mount driving means within the housing, and, therefore, driving means must be placed outside the housing which is a more costly arrangement.